Idk your riding or your FTP, but as unit myself (c.83kg), i'd recommend a disc brake bike with 50mm wheels, 60 if you mostly ride on the flat. Wide rims, at least 32mm, expensive tyres, so you can really get comfortable (even a 28C tyres would measure over 30mm) & aero (no exposed calbes, integrated cockpit, 36cm bars...)
I've been recommending the LT268, very cheap. A bit dated, not the lightest, but fast. Or go down the rabbit hole of finding something newer, lighter, and for what price. It was the best option i found when i bought these frames in 2023, but many models have come out since.
I own a supersix rim with campag carbon wheels; discs + wide rims are a different world of braking performance, speed & and comfort.
In fact a friend of mine, same size, weight, build, is still on his supersix. Same tyres & tubes. Anywhere but on steep stuff, there's a 20+ watts difference for the same speed. Assumption: our power meters read the same (we never tested that). He's on Assioma and i'm on Vector. His all setup is anti aero, mine is full aero. When we go downhill the speed difference is absolutely staggering.
You can get wheels for 500$, and a frame for 500$. You'd want full hydraulic braking. So basically you'd have to upgrade almost everything.
But that's only my 5 cents
Velobuild was having a clear out of some rim brake frames, last time i checked. You might get lucky there.